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A stenomask is a mouth mask with a built-in microphone. The goal of a stenomask is to allow a person to speak without being heard by other people, and to keep background noise away from the microphone.

A stenomask is useful for speech recognition applications, because it allows voice transcription in noisy environments. Perhaps more importantly, a stenomask silences the user's voice so that it does not interfere with the surrounding environment such as a court or a classroom. The user can verbally identify the speaker, indicate gestures and unspoken answers, and describe activities as they take place.[1]

An operator of a stenomask can be trained to "re-voice" everything they hear into a stenomask connected to a speech recognition system, for a real-time text transcription of everything spoken. This allows a "voice writer" to produce instant text feeds within a courtroom and distribute them in ASCII format immediately after a proceeding. The equipment can also interface with litigation management software.

A trained operator using a stenomask connected to a pre-trained speech recognition system can exceed 180 words per minute while at the same time exceeding 95 percent accuracy. They may also modify the pronunciation of the words they are speaking in order to improve accuracy.


The stenomask was developed by Horace Webb and two colleagues in the early 1940s. He was proficient with Gregg shorthand but sought a more accurate and faster system of transcription, as shorthand notes can become unmanageable with fast talkers or difficult terminology. Furthermore, until recently, shorthand reporters would verbally dictate transcription notes into typewritten form, resulting in about two hours dictation for every hour transcribing.

Thus, Webb thought he could "repeat it with my voice instead of with a pen". After much experimentation—first with a cigar box and then a tomato can—he arrived at a solution using a microphone inside a rubber Air Force face mask, paired with a coffee pot filled with sound-absorbing material. The result was eventually deemed by the U.S. Navy to be the most accurate method of transcription among "all known systems of verbatim reporting", and was subsequently adopted for use in their court reporting.[2]

Continuing in his father's footsteps, Stephen Webb (Talk Technologies, Inc.) is contributing major advancements to the classical "moose-mask" design. These improvements include a smaller, lightweight design, and a specially designed mask to be used for speech recognition.


  1. Voice Writing: The Method, National Verbatim Reporters Assoc, retrieved 13 Mar 2007
  2. The Horace Webb Story, National Verbatim Reporters Assoc, retrieved 13 Mar 2007

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